The Violence Project Database of Mass Shootings in the United States, 1966–2019 Jillian K. Peterson & James A. Densley November 2019 About The Violence Project The Violence Project is a nonpartisan think tank dedicated to reducing violence in society and improving related policy and practice through research and analysis. We conduct high-quality, high impact, research for public consumption. We also develop and deliver education and training to share research findings and prevent violence. We provide media commentaries and support concerned citizens, K-12 schools, colleges and universities, workplaces, houses of worship, and other public or private clients in their strategic response to violence. Visit us at www.theviolenceproject.org. About This Violence Project In November 2019, The Violence Project will publicly release the largest, most comprehensive database of mass shooters in the United States, developed by professors Jillian Peterson and James Densley and a team of students at Hamline University in St. Paul, Minnesota. The entire database is downloadable for free at www.theviolenceproject.org, but it is vital that it is only used for the purpose of better understanding or preventing mass shootings. This report accompanies the public launch, providing some background on the project and a summary of topline findings. The Violence Project Database of Mass Shootings in the United States, 1966–2019, was supported by Award No. 2018-75-CX-0023, awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect those of the Department of Justice. The Violence Project I 1 About the Authors Jillian K. Peterson, PhD, launched her career as a special investigator in New York City, researching and developing the psycho-social life histories of men facing the death penalty, which were used in their sentencing hearings. In that office she developed a saying - the worse the crime, the worse the story - and it was always true. Since then, Jill has led large-scale research studies on mental illness and crime, school shooting prevention, and mass violence, which have received national media attention. She is a sought-after national trainer and speaker on issues related to mental illness and violence, trauma, forensic psychology, and mass violence. Jill earned her Master’s in social ecology and Doctorate in psychology and social behavior from the University of California, Irvine. She is also trained in restorative justice, violence mediation, crisis intervention, de-escalation, and suicide prevention. Jill is a Professor of Criminology and Criminal Justice at Hamline University and the faculty director of the Center for Justice and Law. James A. Densley, PhD, is a Professor of Criminal Justice and University Scholar at Metropolitan State University, part of the Minnesota State system. He is also a Fellow of the Hamline University Center for Justice and Law and Visiting Professor at the University of West London. Born and raised in England, James first moved to the United States to teach special education in the New York City public schools. After earning his Doctorate in sociology from the University of Oxford, he quickly established himself as one of the world’s leading experts on street gangs and youth violence, including cyber violence. James’ work has attracted global media attention. He is the author of three books, including the award-winning How Gangs Work (Palgrave Macmillan, 2013), 40 refereed articles in leading social science journals, and over 50 book chapters, essays, and other non-refereed works. The Violence Project I 2 Database of Mass Shootings in the United States, 1966–2019 Jillian K. Peterson, Ph.D. James A. Densley, Ph.D. © 2019. This paper is covered by the Creative Commons “Attribution–NoDerivs– NonCommercial” license (see http://creativecommons.org). It may be reproduced in its entirety only if The Violence Project LLC is credited, a link to the Project’s website is provided, and no charge is imposed. The paper may not be reproduced in part or in altered form, or if a fee is charged, without the Project’s permission. Please let the Project know if you reprint. Suggested citation: Peterson, J.K. & Densley, J.A. (2019). The Violence Project Database of Mass Shootings in the United States, 1966–2019. Saint Paul, MN: The Violence Project. Retrieved from https://www.theviolenceproject.org. The Violence Project I 3 Introduction The United States has not one gun violence problem, but several (Densley & Peterson, 2017; PERF, 2019). Everyday gun violence claims or changes hundreds of lives each week, disproportionately young Black and Latino men. In 2017 alone, the Centers for Disease Control reported 14,542 homicides by discharge of firearms. About 106 of those deaths were attributable to mass public shootings, according to our data—the highest of any year recorded because of the Las Vegas shooting that claimed an unprecedented 58 lives. The fact that mass shootings account for fewer than 1% of all firearm homicides does not diminish their extraordinary tragedy—mass shootings cause damage and devastation far beyond that which is measured in lives lost (Fox & DeLateur, 2014). Mass shootings are focusing events (Fleming et al., 2016). And while they are statistically rare (Harding et al., 2002; to the extent that the actual risk of being killed in a mass shooting is smaller than the risk of being struck by lightning), in the United States they are certainly routine. Mass shootings have been occurring since at least August 1903, when a war veteran deliberately fired into a crowd of people in Winfield Kansas, killing nine and wounding 25, before turning the revolver on himself. In the first half of the 20th Century, there were a handful of mass shootings, including the infamous “walk of death” in September 1949, where another ex-military man, targeting local shopkeepers whom he believed had aggrieved him, killed 13 in Camden, New Jersey. These early crimes didn’t lack for publicity, but the watershed moment for public awareness of mass shootings was the summer of 1966. In August of that year, a former Eagle Scout and Marine shot and killed 15 people from a 28th floor observation deck on the University of Texas The Violence Project I 4 campus in Austin. What set the Texas clocktower shooting apart was that it unfolded live over the radio and the new medium of television—reporters on the scene described the events as they happened. Our study goes back to the Texas tower shooting in 1966 for this reason— mass shootings since then have received sufficient news coverage to be able to reconstruct and study them. The term “mass shooting” is quite new. Before the early 2000s, it was much more common to speak of massacres, slayings, rampage shootings, mass killings, multiple homicides, bloodbaths, even “going postal.” A mass shooting is a modern variant on mass murder, but the more generic term lumps together cases that vary along what researchers agree are important dimensions: time, place, and method (Duwe, 2007). Someone who kills their victims in separate events is different from someone who kills them all at once. A person who kills in public is different from a person who kills in private, especially when private victims tend to be family members; and different still from a contract killer, bank robber, or gang member who kills in the commission of another crime. An arsonist or bomber is different from an active shooter. There is no universally accepted definition of a mass shooting. The U.S. Federal Bureau of Investigation (FBI) do not officially define one nor do they use the term in their Uniform Crime Report statistics; instead, federal authorities tend to focus on “active shooters” (e.g., Blair & Schweit, 2014). In the 1980s, however, the FBI established a definition for “mass murder” as “four or more victims slain, in one event, in one location,” excluding the offender if they committed suicide or were killed in a justifiable homicide (Krouse & Richardson, 2015, p. 4). By extension, the most commonly accepted definition of a mass shooting is an incident in which The Violence Project I 5 four or more victims are killed publicly with guns within 24 hours (Duwe, 2007). In this tradition, we follow the Congressional Research Service definition: …a multiple homicide incident in which four or more victims are murdered with firearms—not including the offender(s)—within one event, and at least some of the murders occurred in a public location or locations in close geographical proximity (e.g., a workplace, school, restaurant, or other public settings), and the murders are not attributable to any other underlying criminal activity or commonplace circumstance (armed robbery, criminal competition, insurance fraud, argument, or romantic triangle). (Krouse & Richardson, 2015, p. 10) We acknowledge the limits of this definition. Every mass casualty event is a tragedy and many factors influence whether a threshold of four or more people killed is reached, including the accuracy of the shooter, the type and caliber of weapon used, the number of rounds fired, proximity to the nearest hospital, and if/how many bullets hit vital organs. However, the number of deaths is the strongest predictor of media coverage (Duwe, 2000), which is necessary to accurately track mass shootings. By focusing only on public events, we exclude domestic mass shootings (if 50% or more of victims are non-relatives killed in public then we include them), which are the most common form of mass shootings (Krouse & Richardson, 2015). We also exclude mass shootings attributable to underlying criminal activity, and events where a firearm was not the primary means of death. A broader definition with a threshold of fewer deaths, non-fatal shootings, or any means or motive would certainly yield more cases.